1. Field of the Invention
The present inventions relate to abrading and cutting devices and methods, and more specifically to waste containment systems and methods for such devices and methods, for example slurry containment systems and methods for saws, cutters and the like.
2. Related Art
Pavement treatment apparatus and methods are known for concrete and asphalt saws which may include a vacuum apparatus for removing water and particulate matter, commonly referred to as slurry, from a work site. See Bassols, U.S. Pat. No. 5,564,408, entitled Pavement Treatment Method and Apparatus, the specification and drawings of which are incorporated herein by reference. As discussed in that patent, concrete and asphalt saws are typically used to cut joints for expansion and contraction of such materials in freeway pavement, aircraft runways, and other pavement surfaces. Typical saws are marketed under different brand names and include a diamond blade of different diameters according to the thickness of the pavement to be cut, such as 12, 14, 16, or 24 -inch blades, etc., driven by an internal combustion engine. The engine is also used to drive a traction mechanism at the rear of the saw for advancing the saw along the pavement. A belt takes power from a pulley driven by the internal combustion engine for powering a transmission box to step down the revolutions per minute (rpm) of the engine to a suitable rate for driving the traction wheels of the saw and for driving the saw blade.
The saw blade includes a blade guard for protecting the blade during operation and for preventing injury while the blade is rotating. The blade guard also contains cooling water sprayed onto the blade so that the cooling water drops onto the pavement.
The saw also includes a structural support frame for supporting all of the components and for mounting the wheels to the saw. The frame supports the engine, the shaft for driving the saw blade, the traction transmission and the pulleys for powering the traction transmission from the engine, among other elements.
In operation, the saw is started and positioned in alignment with the desired cutting path, and lowered into engagement with the pavement while at the same time turning on the coolant spray to the blade. An additional vehicle or other source is located nearby for supplying water for cooling the blade through a suitable hose. As cutting continues, the water and resulting slurry from the abraded pavement is picked up by a suction or vacuum bar to minimize filling previously cut joints. The slurry and any air picked up by the vacuum bar is taken back to a separator tank for removing the slurry. A disposal hose transports waste from the collection tank through a diaphragm pump to a truck or other container for disposal.
Waste containment systems and methods are described for abrading and cutting apparatus which provide improved removal of slurry and improved operating life of various components in the system. Such systems and methods may be used on saws, such as pavement and concrete saws, other cutting tools, such as wall saws, core drills and other boring equipment, and the like. The systems and methods may be implemented as original equipment or as accessories in kit form or individual components.
In one aspect of one of the inventions, a material pickup element is provided for picking up a fluid, which may include solid particles forming a slurry. The pickup element may be a vacuum bar, vacuum shoe or other suction device, for example. Element includes a number of openings comprising at least one and preferably a set of low vacuum apertures and at least one and preferably a second set of high vacuum apertures. In a preferred embodiment, the high vacuum apertures pickup most if not all of the slurry, and the low vacuum apertures focus, collect, concentrate or align the slurry so that it can be more easily picked up by the high vacuum apertures. For example, the low vacuum apertures can center or bring in fluid from both sides of the vacuum element so that an adjacent high vacuum aperture can pickup the slurry. Using both low and high vacuum apertures helps to conserve vacuum pressure, or minimize the loss of vacuum through larger openings, especially where the amount of vacuum available is limited or fixed. Conversely, using both low and high vacuum apertures permits placement of high vacuum areas where they may be most beneficial, and reduction of aperture size at other areas of the pickup element where high vacuum would not have significant incremental value over others already included.
In one preferred form of the pickup element, the low vacuum apertures are round or similar holes and the high vacuum apertures are extended slots in the pickup element. The round holes may be grouped in a series, and the round holes may be co-linear with a slot. Other configurations, arrangements and orientations for the openings can be used.
In one preferred aspect of one of the inventions, the pickup element is used on a concrete or similar saw which moves along the work surface. The openings are preferably distributed over the pickup element so as to take advantage of the forward or backward motion of the saw. In one preferred embodiment, the high vacuum apertures are placed in front of the low vacuum apertures, which in turn may be followed by one or more additional high vacuum apertures. Alternatively, high and low vacuum apertures may alternate along the pickup element, for example beginning and ending with high vacuum apertures. The pickup element can then bring in fluid from both sides of the element, minimize or limit flow over the work surface and tailor the location or flow of the slurry relative to the pickup element.
In a further preferred aspect of one of the inventions, one or more of the apertures or openings may extend along a surface of the pickup element in a direction at least partly perpendicular to the work surface. For example, in a vacuum bar that extends horizontally, most of the apertures can open downwardly and extend horizontally over a horizontal surface of the vacuum bar and a high vacuum aperture can extend vertically or in a direction other than downwardly. A vertically extending high vacuum aperture can be advantageous directly behind the saw blade.
In a further aspect of one of the inventions, a system can be used for designing pickup elements. The system can include a processor or computer loaded with a computational fluid dynamics fluid flow optimizing program to optimize the flow of the slurry and maximize the suction created by the fan. Input parameters include maximum vacuum available, desired fluid flow rates through the pickup element, and the like. The system preferably identifies possible as well as optimum sizes and configurations for pickup elements, and potential and optimum sizes, configurations and distributions of vacuum openings. In one preferred embodiment, the system is used to identify the sizes, shapes and locations of openings to be used for picking up slurry, in addition to the sizes, shapes and locations of openings to be used for focusing, channeling or otherwise controlling flow of the slurry away from the pickup element.
In a further aspect of one of the inventions, the pickup element can include removable end caps having curved surfaces for more easily negotiating or riding over pebbles or other objects which may be in the line of travel. Having removable end caps makes for easier cleaning of the pickup element.
In another aspect of one of the inventions, a tool guard such as a blade guard includes a water supply conduit or tube for projecting or spraying fluid onto the tool. The fluid may be used as a lubricant and/or coolant for the tool. The fluid is directed toward the tool at an angle different than 90 degrees. For example, the fluid can be directed backward toward an on-coming surface of the tool. Directing the fluid backward relative to the motion of the tool reduces the amount of fluid thrown forward of the tool. Consequently, the amount of fluid to be picked up at the front of the tool is reduced. In one preferred embodiment, the fluid is directed backward about three degrees from a line perpendicular to the tool, such as a blade.
In a further aspect of one of the inventions, a separation system and method are provided for separating air and a second fluid. A receptacle is provided for receiving a combination of air and the second fluid, the receptacle including at least two vertically extending walls joining at a vertically extending angle. An inlet receives a combination of air and the second fluid and allows the combination to flow into the receptacle. A first outlet passes the second fluid from the receptacle and a second outlet passes air from the receptacle. This configuration contributes to providing a receptacle which more completely separates the air from the second fluid. This configuration makes the flow and disposition of the second material more controlled or organized, while promoting more uncontrolled or disorganized air flow. This type of receptacle configuration also reduces any tendency toward cyclone-type action in the fluid flow, for the air and for the second fluid. It also reduces the amount of symmetry in the surfaces in the receptacle, and in combination with other features, reduces residual splashing of the second fluid.
In another aspect of one of the present inventions, an inlet for a separation system discharges the air and fluid combination closer to the bottom of the receptacle than to the top. With this configuration, the fluid has a shorter distance to travel to the bottom of the receptacle, reducing the amount of splashing and reducing the amount of time the moving air from the inlet is around the moving fluid from the inlet. Additionally, when the outlet for the air is at the top of the receptacle, the air will have more time and area for shedding fluid before leaving the receptacle.
Consequently, the air leaving the receptacle has a lower fluid content. Furthermore, where the fluid has abrasive, corrosive or other harmful material, the amount of harmful material leaving the receptacle through the air outlet and reaching other components is reduced.
In an additional aspect of one of the present inventions, an air outlet for a receptacle in a separation system is positioned off of a line, axis or plane of symmetry. Positioning of the air outlet in this way removes air that is less controlled or less organized earlier than air in other locations of the receptacle where the air may be more channeled. In one preferred embodiment, the only plane or line of symmetry for the air outlet is one between vertically extending walls of the receptacle. Locating the air outlet on this plane of symmetry reduces the possibility of exiting air pulling with it condensed fluid from either of the walls.
In a further aspect of one of the present inventions, an inlet for a separation system discharges an air and fluid combination into a receptacle between two vertically extending walls, and closer to one vertically extending wall than to the other. This asymmetry tends to reduce splashing of the second fluid and contributes to greater control, containment or organization of the second fluid.
In one aspect of the present inventions, a tool is provided for working a material, such as cutting concrete, where the tool is driven by a drive element, such as a drive shaft. Vacuum is created by a vacuum generator driven by the same drive shaft that drives the tool. Such a design provides for a compact and self-contained combination of tool and waste containment system. The design also makes it easier to assemble the combination as a tool and kit for easy assembly and disassembly.
These and other aspects of the present inventions will be better understood after a consideration of the drawings, a brief description of which follows, and the detailed description of the preferred embodiments of the inventions.